Different types of power converters are normally used for providing power to electronic circuits, often these power converters are placed on circuit boards.
A typical power converter comprises switching elements which are controlled by a Pulse Width Modulator (PWM) that delivers the right dv/dt that determines the voltage that needs to be rectified. Rectification is used to be done with diodes, but due to a relatively high voltage drop, diodes are often replaced with rectification elements consisting of transistors, using a rectifying technique called synchronous rectification, where the transistors exhibit much lower voltage drop and thus cutting down power loss.
Power converters which are controlled by a PWM have traditionally been analogue, but are now being digitally controlled to a larger extent.
The transistors in a synchronous rectification need to be controlled in a precise manner so they conduct in the right moment. Otherwise large conduction losses are expected with RF and EMI problems. Problems that need to be accounted are cross conduction and body diode conduction.
Today, a technique with dead times to prevent this scenario is used, but the dead times must be adjustable against load, temperature, input and output voltage, component deviations and aging. In real life, a compromise is used by adding more power loss than optimum to be able to cover all these circumstances. Strictly theoretically, dead times should not be necessary, but, as the skilled person is well aware of, dead times are practically necessary for the function of PWM power converters which are PWM controlled with synchronously controlled switch elements.
In order to optimize the dead time, it must be changed in accordance to the variations mentioned above. This is possible in analogue circuits, but hard to realize as it add a lot of cost and complexity with no commercial interest.
There are no overall solutions today for optimizing the dead times. Analogue solutions for the whole problem are not cost effective or feasible in industrializations.
There is thus a need for a more optimization of dead times in power converters.